1. Field of the Invention
The present invention relates to an apparatus and method for verifying the identification of individuals through their subcutaneous vein structures in the back of the hand, and more particularly, to an apparatus and method for verifying a person's identity in an access control environment which obtains a vein pattern from subcutaneous vein structures in the back of the hand, extracts vein features from the vein pattern utilizing its branching characteristics, and compares the vein features with previously stored reference features of the person. In addition, the present invention relates to an integrated system for verification of thousands of persons based on the apparatus and method.
2. Brief Description of the Prior Art
In current access control systems for security and employee management, the identity of an individual is usually verified either by a magnetic strip on a card or by an RF signal from a contactless card. Recently, a high-cost smart card with high storage capacity has been researched and developed for practical use in access control systems. Practical recognition systems using the fingerprint or face of an individual are also being developed for application to access control systems requiring high security.
These current methods of verification in access control systems have their own disadvantages as well as advantages. For example, the method using card keys or smart cards cannot prevent unauthorized persons from using the cards, and in addition, the method is costly when it is used on a large scale because so many cards are necessary. Fingerprints may not be repeatable features to particular classes of persons such as physical laborers whose fingerprints are likely to be rubbed out due to hard work over a long time. Access control systems based on face recognition are difficult to apply on a large scale because of the inconvenience in installing and operating them.
In order to alleviate the inconvenience of prior methods, an apparatus for identifying individuals through their three dimensional hand shapes was invented and filed in Korea on Apr. 14, 1997. The invention is effective and simple to use. It is, however, necessary to update the data representing the hand shape of each individual periodically because the hand shape is subject to change with time. Errors may occur in verifying the identities of individuals who have not used the apparatus for a long time. Moreover, performance of the apparatus is susceptible to small changes of the position and orientation of the hand caused by elasticity of flesh of the hand even though the hand is fixated by an arbitrary means for fixation.